Such systems are known in the art, in particular in the art of fabricating securities made of paper substrate or the like.
As a first example, U.S. Pat. No. 3,939,621, the content of which is enclosed by reference in the present application, discloses a method of processing sheets of printed security papers into bundles and packets. In this known process, sheets with printed numbered banknotes are supplied to a cutting machine in piles of 100 sheets. After trimming of edges of the pile, successive strips are cut in the pile, each strip having several banknotes in a row. In the given example, each sheet contains 24 printed banknotes arranged in four columns and six rows, thus four strips are produced with six banknotes each. A further cutting unit is provided which then cuts the strips into individual piles of 100 banknotes. The individual piles of 100 banknotes are then individually banded in a banding unit to produce banded bundles of 100 notes consecutively numbered.
U.S. Pat. No. 4,283,902 discloses another process and apparatus for converting piles of freshly printed sheets of banknotes into bundles of banknotes. The disclosed machine comprises as many banding devices as there are individual banknotes per strip, the banding devices operating simultaneously on each strip. Accordingly, the bundled strips are simultaneously provided with bands at all banknote positions, so that the bundles of banknotes leaving the last cutting tool are already banded and the narrow path which the banding station represented in the apparatus known hitherto is eliminated.
Another example is given by U.S. Pat. No. 4,453,707, the content of which is incorporated by reference in the present application, which relates to a method and device for automatically processing sheet piles of numbered multiple-note security papers, such a banknotes, into bundled packets.
A further example of a banding device and banding process is disclosed in PCT application WO 95/19913, corresponding to U.S. Pat. No. 5,755,084, both incorporated by reference in the present application. Said publications disclose a device for arranging a band of flexible material around at least one product, comprising a feed mechanism for feeding band material from a supply roll, means for forming a loop in an end portion of the band material round a space for receiving the product, means for severing that end portion and welding means for closing the loop, the means for forming the loop consisting of transporting means for the band material movable round the space and suction means connected to the transporting means.
In the described device, the band material is pushed up via a guide by feed and pulling rollers and then comes into contact with a perforated endless conveyor belt. The belt, driven by a motor, is in a casing in which a vacuum pump creates underpressure (vacuum) in a channel engaging round the belt. The perforated belt thus draws the band material until the leading end of the band is clamped by a clamp. A space is surrounded by the band material, said space being larger than the product to be banded placed herein. Feed and pulling rollers then tighten the band material until the band material fits around the product, the band material coming loose from the perforated belt. Finally, cutting and welding means close the loop of band material and sever it from the remaining band material. The product banded can be removed and the machine is ready for the following cycle.
This machine is however not practical when using it for banding a strip of notes in a simultaneous manner as is usual in the art of producing printed document such as securities. With several banding units arranged next to each other (as many banding units as single notes in the strip), the strip must be transported laterally under the successive banding units in order to be in place in banding position, which is very time consuming, since the means for forming the loop are rigidly connected to the machine body side.
Document DE 101 60 718 describes a banding system comprising means for forming a loop around the products to be banded which are movable upwardly and downwardly with respect to a stationary machine body so as to allow the products to be transferred in the banding position between an opening created between the means for forming the loop and the machine body. This document does not however disclose how the band material is or might be transported around the product, or how the means for forming the loop is operatively connected to the remaining of the machine. There is in particular no indication or suggestion in this document that the band material is or could be transported by means of a vacuum-assisted transport system. Moreover, in DE 101 60 718, the means for forming the loop are displaceable by means of a supporting frame oriented perpendicularly to the transport path of the band material and which therefore limits the dimensions, lengthwise (i.e. in the direction perpendicular to the transport path of the band material), of the products to be banded. This constructions also creates complications and is too bulky should one desire to dispose several banding system in parallel, in order for instance to band several portions of a same strip of piled products.